Is the sequence pattern for the coefficients of (k + y)^n an arithmetic sequence, a geometric sequence, or neither?

For all objects j, if j is a square then j has four sides a. all b.every c.if an object is a square,then d.if then e.for all squares

Atank contains 80 gallons of pure water. a brine solution with 2 ; b/gal of salt enters at 2 gal/min and the well stirred mixture leaves at the same rate. find the amount of salt in the tank at any time and the time at which the brine leaving will contain 1 lb/ gal of salt? ​

Yis a multiple of to translate to mathematical symbols? ? ​